Make .config.old easier to discover

Mention that the old version of an overwritten configuration file is
saved to <filename>.old in a few different places, to make it easier to
discover.

6 files changed, 18 insertions, 0 deletions

diff --git a/README.rst b/README.rst
index 8315e07..3e2119e 100644
--- a/README.rst
+++ b/README.rst
@@ -164,6 +164,9 @@ Getting started
    implicit ``olddefconfig``, so building will normally not be affected by
    having an outdated configuration.
 
+Whenever ``.config`` is overwritten, the previous version of the file is saved
+to ``.config.old`` (or, more generally, to ``$KCONFIG_CONFIG.old``).
+
 For some general Kconfig advice, see `this page
 <https://docs.zephyrproject.org/latest/guides/kconfig/index.html>`__.
 
diff --git a/guiconfig.py b/guiconfig.py
index 0ff5fa0..c709c4e 100755
--- a/guiconfig.py
+++ b/guiconfig.py
@@ -41,6 +41,9 @@ as a command-line argument. With no argument, it defaults to "Kconfig".
 The KCONFIG_CONFIG environment variable specifies the .config file to load (if
 it exists) and save. If KCONFIG_CONFIG is unset, ".config" is used.
 
+When overwriting a configuration file, the old version is saved to
+<filename>.old (e.g. .config.old).
+
 $srctree is supported through Kconfiglib.
 """
 
diff --git a/menuconfig.py b/menuconfig.py
index 892443c..8160c03 100755
--- a/menuconfig.py
+++ b/menuconfig.py
@@ -55,6 +55,9 @@ as a command-line argument. With no argument, it defaults to "Kconfig".
 The KCONFIG_CONFIG environment variable specifies the .config file to load (if
 it exists) and save. If KCONFIG_CONFIG is unset, ".config" is used.
 
+When overwriting a configuration file, the old version is saved to
+<filename>.old (e.g. .config.old).
+
 $srctree is supported through Kconfiglib.
 
 
diff --git a/oldconfig.py b/oldconfig.py
index 4379dcf..387b42e 100755
--- a/oldconfig.py
+++ b/oldconfig.py
@@ -14,6 +14,9 @@ Implements oldconfig functionality.
 The default input/output filename is '.config'. A different filename can be
 passed in the KCONFIG_CONFIG environment variable.
 
+When overwriting a configuration file, the old version is saved to
+<filename>.old (e.g. .config.old).
+
 Entering '?' displays the help text of the symbol/choice, if any.
 
 Unlike 'make oldconfig', this script doesn't print menu titles and comments,
diff --git a/olddefconfig.py b/olddefconfig.py
index c985bfa..1d1bac1 100755
--- a/olddefconfig.py
+++ b/olddefconfig.py
@@ -11,6 +11,9 @@ saving.
 
 The default input/output filename is '.config'. A different filename can be
 passed in the KCONFIG_CONFIG environment variable.
+
+When overwriting a configuration file, the old version is saved to
+<filename>.old (e.g. .config.old).
 """
 import kconfiglib
 
diff --git a/setconfig.py b/setconfig.py
index 4c41529..c92f346 100755
--- a/setconfig.py
+++ b/setconfig.py
@@ -16,6 +16,9 @@ The exit status on errors is 1.
 
 The default input/output configuration file is '.config'. A different filename
 can be passed in the KCONFIG_CONFIG environment variable.
+
+When overwriting a configuration file, the old version is saved to
+<filename>.old (e.g. .config.old).
 """
 import argparse
 import sys